An arrangement of the above general kind is disclosed in U.S. Pat. No. 3,447,647, whereby a space-saving reduction of the distance from the end of the push rod to the brake block holder surface accomodating the brake block is attained. Such a reduction is of great importance in many cases, as the space available on modern rail vehicles for brake actuators with brake block holders often is extremely limited.
A more conventional arrangement without this space-saving reduction is shown in DE-C-1 809 556, where the push rod has a tapering or V-shaped end force-transmittingly cooperating with a corresponding groove in a cube, which is arranged on the shaft pivotally connecting the brake block holder to the brake block hangers.
In this conventional arrangement the guiding and torque transmission between the push rod and the brake block holder is provided by the cooperation betwen the V-shaped push rod end and the corresponding groove in the cube, whereas there is a friction device between the brake block holder and the brake block hangers for keeping the brake block holder in a proper position for braking cooperation with a wheel to be braked. However, with this conventional design the brake block holder will follow the brake block hangers in their arcuate movements.